A known torque converter apparatus disclosed in JP2004-301327A (hereinafter referred to as Reference 1) or the fifth report on History of Transmission (JatcoJR508E) published by Society of Automotive Engineering of Japan, Inc. (June, 2008) includes a bridging clutch serving as a lock-up clutch and a torsional vibration damper serving as a lock-up damper. The bridging clutch is arranged between an engine and an output element of the torque converter so as to mechanically transmit torque from the engine to a transmission. The torsional vibration damper functions to reduce muffled noise caused by vibrations of the engine.
The aforementioned bridging clutch includes an independent oil passage. A clutch engagement pressure is supplied to the bridging clutch through the independent oil passage. The bridging clutch includes a support portion serving as an outer hub supporting disks (frictional engagement members) and integrally rotating with a driving-side housing (front cover) of the torque converter apparatus.
The aforementioned torsional vibration damper does not include a plurality of springs arranged apart from one another in a radial direction of the torque converter.
In particular, the support portion described in Reference 1 is arranged at an outward side of the torsional vibration damper in the radial direction of the torque converter, therefore increasing the size of the torque converter in the radial direction and limiting the size of the torsional vibration damper in the radial direction. Accordingly, in a case where the torsional vibration damper includes the plurality of springs, the size of the torque converter apparatus in the radial direction is further increased and the size of the torsional vibration damper in the radial direction is further limited.
A need thus exists for a torque converter apparatus, which is not susceptible to the drawback mentioned above.